James wrote:

Following the link you posted, the Rei discussed in the article "The Search for Rei" is not the rei indicating spirit but rather the rei indicating proper attitude and conduct;
ones demeanour, and manner – how one interacts with others:



This is a common theme in Japanese martial arts

This rei is about formal etiquette (reigi) politeness, good manners,– also about showing respect , consideration; and gratitude

Its the same Rei as in 'Gassho Rei ' ( the 'Gassho Bow' )

and as in:

reiki ni rei